<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>

<script>

    function foo(a,b){
        alert(a);
        alert(b);
        console.log(this);
    }
    var obj = {
        name:'frank',
        age:20
    }
//    foo.call(window);
//    foo.call(obj,'frank','tom');// obj
//    foo.apply(obj,['frank','tom'])

    //window


</script>
<script>

</script>
</body>
</html>